Flashlight lamp



P. scHwARzE FLASHLIGHT LAMP Filed Sept. 14. 1937 INVENTOR Patented Apr. 16, 1940 UNITED sTAr-ss PATENT- o'F icE v Paul Schwarze, St.

Gallen, Switzerland I 6 Claims.

' The known. flashlight lamps of the type, in which light is produced by the reaction of suit- 'able substances, enclosed in gas tight vessels, are complicated and expensive to manufacture. They generally comprise glass bulbs in the form of ordinary incandescent lamps and contain aluminium foils as light developing substance. Asthe oxygen required for the combustion can only have a very slight pressure, in order to avoid explosions, it is necessary to provide comparatively large glass bulbs for producing suiiicient light. This renders the conveyance of large quantitles, as is necessary [for examplei'n thecase of photo-reporters, rather difficult. A further. de-: fect of the known lamps is that in spite of the slight oxygen pressure the lamps sometimes ex.-

plode and it has happened that this has led to fires and injuries. Hitherto it has not beenpossible in practice to eliminate. entirely this dangerous explosion of the flashlightlamps, although experiments have shown that when the lamp is ignited the pressure developing within the lamp is generally not greater than atmospheric. The reason is to be sought in the inaccuracy of manufacture, because otherwise the"; costs of production of an article which can only be used once would be rendered prohibitive in practice, and

tible foils, in order to. compensate for the increase I of pressure, but theynecessitate additional. de-

vices to prevent the issuance of the flame and smoke. l

According to the present invention these defects of the known flashlight lamps are eliminated by making the flashlight vessel of a gas tight, tough material, e. g. metal, preferably in the form of a flat box closed by a window for the passage of the light and consisting of a gas tight material offering sufiicient resistance to the comsiderably smaller vessel than hitherto and when necessary the oxygen may be maintained therein at a correspondingly higher pressure. Experiments have proved that the gas charge can be increased to atmospheric or even higher pressure, if suitable material of sufficient strengthis used} The sealing of the window is effected with the aid of vacuum cement, white sealing wax or the like but in order to prevent the intrusion of air reliably in all transport, storage or climatic conditions the parts to be sealed may be firmly pressed to one another by means of suitable devices or suitable shaping, preferably by {screwing 10 on, with the interposition of a packing of rubber a or the like. i j

In the accompanying drawing embodiments of the invention are illustrated by way of example.

Figs. '1, 2 and 3 are sections through a fiash- 15 light lamp according to the invention.

In Fig. 1, theflashlight lamp consistsof .-the box 8 of gastight, tough materialget g. metal. It is filledwitha flashlight charge, adapted to emit light by reaction of its components, as for instancemetal in the form of foil or powder and oxygen. 2 is a disc of special or ordinary glass of sufiicient strength, which closes the box in an air tight manner with the aid of the vacuum cement 3. 4, isv a primer with the .aid of which the flashlight substance is, ignited, in the em-j bodimentshown in Fig. 1 mechanically, for example through a firing pin'.

A further useful arrangement of the flashlight lamp is illustrated in Fig. 2. The lower part of the bOX' l is the combustion chamber, ,which is closed'by the transparent skin or pane 5 and which contains the flashlight charge. Above this there is a space 8, which is sealed in agas tight. manner by the window 2. The space 8 acts as a buffer chamber or receiving space for the combustion. pressure. The pressure in same is conveniently of the same value as in the combustion space. In this figure 9 indicates openings for the evacuation of the air and for. charging the oxygen., These openings may be closed by pinching or with vacuum cement or the like. In this embodiment the ignitionis provided in the well known electrical form. 4 is the igniting filament, one end of which may be directly attached to the box if this is made of conductive. material. Fig. 3 shows an embodiment in which for better sealing the window is pressed to the box by screwing it on. In this figure 3 is a packing ring of rubber, leather or the like: 5 is a Cellophane skin which may at onepoint be provided with a fine hole. I is the lid, the side edges of which are formed witha thread corresponding to that of the box I. The major part of the upper side of the lid is apertured for thewindow 2 and the I when the lid is screwed on. TheCellophane skin 5 resists .the first gas pressure at the combustion and also serves to receive the precipitate of the residues of combustion, therebykeeping the window clean. This skin may however be omitted. The box and window may also be pressed together by other means, for example by springy stirrups or by clamping suitable substances between the disc 2 and the ring '3 and so forth. The form shown in Fig. 3 may also be embodied by making the whole box l of glass and forming 2 as a closed metal lid without a disc. This embodiment would in exterior appearance resemble the well known preserve jars.

stan'c'es the combustion space can be wholly or partly evacuated. If two reacting gases are employed, one gas may be introduced into each of the two spaces shown in the embodiment according to Fig. 2, since greater durability is ensured by the separation of the gases. case the primer can befprovided on the skin 5, so that this may be pierced upon ignition, thereby bringing about the reaction of the gases.-

For evacuating the boxes and filling them with oxygen or other gases of atmospheric pressure they may have instead of the opening or openings 9 shown in Fig. 2, a plain hole of extremely small diameter. They can then be placed in considerable numbers in receptacles for evacuation and refilling and the small holes can subsequently be sealed in any convenient manner without any considerable loss of gas.

' The flashlight lamp according to the invention has the additional great advantage, especially in the embodiment shown in 3, that the main parts may be used again by refilling them with a new flashlight charge, which is impossiblein the known flashlight lamps consisting of glass bulbs.

What I claim as my invention and desire to secure by Letters Patent of the United States is:

l. A flashlight lamp particularly for photographic purposes, comprising a vessel of gas tight, tough material; atransparent window, for the passage of the light, sealed to an opening of said vessel in a gas tight manner and adapted to re- In the latter sist the combustion pressure produced; a flashlight charge in said vessel adapted to emit light by reaction of its components and means for ig-' niting said charge within said vessel.

2. A flashlight lamp particularly for photo' graphic, purposes, comprising a vessel of gas material sealed to an opening of said, vessel in a gas tight manner and adapted to resistthe com bustion pressure produced; a second window of tight, tough material; a window of transparent adapted to emit light by reaction of its components and means for igniting said charge within the said vessel.

3. A flashlight lamp particularly for photographic purposes, comprising a vessel of gas tight, tough material; a window of transparent material sealed to an opening of said vesselin a gas tight manner by being pressed on to it with the interposition of a packing and adapted to resist the combustion pressure produced; and a flashlight charge in said vessel adapted. to emit light by reaction of its components.

, 4. A flashlight lamp particularly for photographic purposes, comprising a vessel of gas tight, toughmaterial, theside edges of which are formed as screw threads; alid adapted'to be screwed on to said vessel by means of corresponding screw threads in its side edges; a window of transparent material in the lid and a flashlight tight, tough material; a transparent window for 'f the passage of the light, sealed to an opening of said vessel in a gas tight manner and adapted to' resist the combustion pressure produced; a flashlight charge in said vessel consisting of oxidizable metal and oxygen at substantially at-- mospheric pressure 'and'means for igniting said charge within the said vessel.

6. A flashlight lamp particularly for photographic purposes, comprising a box-shaped vessel of gas-tighh tcugh material; a transparent window forthe passage of the light, sealed to an opening of said vessel in a gas-tight manner and adapted to resist the combustion pressure pro.- I

duced; a flashlight charge in said vessel adapted to emit light by reaction of its components; and

means for igniting said charge within the said vessel.

P. SCHWARZE. 

